uboot-imx

MA-14898 Fix build warnings

Include correct header files to avoid build warning:
  common/image-android.c:151:68: warning: implicit declaration
  of function ‘mmc_get_env_dev’ [-Wimplicit-function-declaration]
  " androidboot.boot_device_root=mmcblk%d", mmc_map_to_kernel_blk(mmc_get_env_dev()));

Change-Id: I932a178500e7397f72d717efae0dd2d954a909d8
Signed-off-by: Ji Luo <ji.luo@nxp.com>